To influence a final thickness profile of a rolled strip in a mill train having a plurality of roll stands, the influence on the thickness profile of the rolled strip must be distributed among several roll stands. For a suitable influence, values for the final thickness profile of the rolled strip after the individual roll stand must be available. Because it is difficult and expensive to measure the thickness profile of a rolled strip, the thickness profile of the rolled strip is usually measured at a single location. For example, the thickness profile of a rolled strip (p.sub.i) downstream from the individual roll stands, and ultimately the final thickness profile, i.e., the thickness profile downstream from the final roll stand, can be determined by repeated use of the relationship: ##EQU1## In equation (1), k.sub.i is calculated as follows: ##EQU2## Such calculations are discussed in "High-Accuracy and Rapid-Response Hot Strip Mill," TECHNO Japan, Vol. 20, No. 9, September 1987, pp. 54-59. In the above equations, P.sub.i-1 is the thickness profile of the rolled strip upstream from the roll stand; h.sub.i-1 is the strip thickness upstream from the roll stand; h.sub.i is the strip thickness downstream from the roll stand; .pi..sub.i is a load roll nip profile; D.sub.i is a working roll diameter; b is the thickness of the rolled strip; and c.sub.i1 and c.sub.i2 are model parameters. The factor k.sub.i is determined from analytical relationships, which take into account certain properties of the roll stand and the rolling stock.
A disadvantage of such a formulation is that the equations (2) and (3) are only approximately valid. Furthermore, the model parameters c.sub.i1 and c.sub.i2 are unknown and must be determined experimentally. This often leads to an inadequate determination of the thickness profile